L&M Newsletter

Fuel Line Calculator

By: Michael Rauscher

Reminder these are for ideal conditions and real life results will vary greatly. This calculator is useful for calculating velocities and theoretical pressure loss.

Fuel Line Calculation Equation

  • f = D'Arcy-Weisbach friction coefficient
  • Re = Reynolds Number
  • dh = hydraulic diameter (m, ft)
  • ε = Roughness height, (m, ft)


Average Specific Gravity

Plug in your own values to replace these theoretical values. Specific gravity will vary with temperature.

D'Arcy-Weisbach Friction Coefficient

Average D'Arcy-Weisbach Friction Coefficient for smooth hose, drawn steel tube, aluminum tube with recommended Reynolds numbers.


Ideal sizing would result in velocities between 1 - 4 feet per second. Higher velocities will result in turbulent flow.

Pressure Loss